DE10118449C1 - Device for monitoring a chemical stream used in the synthesis of DNA comprises a base body having a tubular recess, light measuring paths represented by light sources and a light - Google Patents

Abstract

Device for monitoring a chemical stream comprises a base body (1) having a tubular recess (14) for receiving a light-permeable tubing (15); light measuring paths represented by light sources (4, 5, 6) and a light sensor (9, 10, 11) for measuring the light intensity of a light beam bundle; and an evaluating unit. Device for monitoring a chemical stream comprises a base body (1) having a tubular recess (14) for receiving a light-permeable tubing (15); light measuring paths represented by light sources (4, 5, 6) and a light sensor (9, 10, 11) for measuring the light intensity of a light beam bundle; and an evaluating unit. The light sources and the sensor are arranged diametrically to the tubular recess so that a light beam bundle emitted by the light sources is received by the sensor.

Description

The invention relates to a device for monitoring a chemical flow.

Devices for monitoring a chemical flow are used in devices for Implementation of chemical and / or biological reactions used. Such The device is known, for example, from WO 00/40330 A2.

A known device for monitoring a chemical flow has Light source on a light emitting diode, the light, of a certain wavelength range radiates. The light beam of the diode will be translucent Hose directed in which the chemical flow flows. That from the hose emerging light is received with a light sensor. Because different Che different colors, the light from the chemicals absorbed to different degrees. The output signal of the light sensor is proportional nal to the intensity of the received light.  

This known device for monitoring a chemical flow is based on a certain light permeability of the chemical flow is set. In the Chemical reactions are carried out after the reaction Abge composition of matter by means of a hose from a reaction chamber leads. This chemical flow is monitored to see whether the set one Brightness is maintained or whether the chemical flow more or less light absorbed. This known device only allows qualitative statements whether egg ne certain light intensity is received or a lower or higher Light intensity is received.

A similar device for monitoring a chemical flow is known from the US 4,816,695 known. This device has a photodiode and light source as a light sensor on a phototransistor that crosses a fluid flow Light detected. The evaluation electronics of this device is for detecting whether a certain threshold value is exceeded, trained. The threshold can be determined using a potentiometer.

EP 0 959 341 A1 discloses a very complex device for analysis of exhaust gases from combustion devices. Here, using light swell light rays through the exhaust gases of the combustion device radiates and the light is received by means of receiving devices and into optical Optical fiber coupled. The light guides are connected to a spectrometer via a multiplexer connected with which receive from the individual receiving devices light rays are spectrally analyzed.

In DE 691 24 600 T2, which corresponds to European Patent EP 0 528 802 a measuring device for measuring the particle size of particles in a Fluid flow described. In this device, the particle flow in several re partial flows and the individual partial flows are separated by means of a light source is illuminated and the light passing through the partial flows becomes detected by means of photo detectors.

The invention has for its object such a device for monitoring Chen a chemical flow in such a way that a precise statement is possible via the chemical flow in the hose, and a use admit this device.

The object is achieved by a device having the features of claim 1 and a use according to claim 16 solves. Advantageous embodiments of the invention are set out in the dependent claims give.

The device according to the invention for monitoring a chemical flow comprises

• - A body that has a tubular recess for receiving a light permeable hose,
• - At least two light measuring sections, each light measuring section by one Light source and a light sensor is shown, and the light source and the light Sensor of a light measuring section diametrically to the tubular recess in such a way are ordered that a light beam emitted by the light source from the Light sensor is received, and
• - An evaluation device which evaluates the light signals emitted by the light sources and received by the light sensors ( 9 , 10 , 11 ) to determine a flow rate and / or a chemical concentration.

The invention provides at least two light measuring sections, the Si gnale combined be evaluated. This enables complex monitoring functions  can be realized, such as detecting multiple differences Licher chemicals in the chemical flow or the determination of the flow speed, resulting in combination with the cross section of the hose the flow rate of the chemical flow can be determined.

In a preferred embodiment of the invention, the light source and the Light sensor positioned such that the light beam emitted by the transmitter from the translucent tube filled with a liquid to about Light sensor is mapped. With such an arrangement, absorption effects can occur and / or refractive effects are quantitatively resolved.

Are two of the light measuring sections in the direction of the chemical flow by one certain distance staggered, the time offset of the signals received from the two light measuring sections are the flow velocities be determined.

According to a preferred embodiment, two light measuring sections intersect a point on the central axis of the tubular recess, and the light sources and light sensors of these light measuring sections are each on different worlds length range matched. With such an arrangement, the same fluid becomes range of the chemical flow from the intersecting light measuring sections detek tiert, so that the signals of the two light measuring sections the same fluid section affect. By comparing the two signals different chemicals can be found can be detected in the chemical flow.

The device according to the invention is in particular for monitoring the chemicals Line flow to a reaction chamber of a device for synthesizing Suitable oligonucleotides, which can be carried out for monitoring in the smallest space, thus no long, correspondingly large dead volume hose are necessary, and thus very precise chemical concentrations and Flow rates can be determined so that the use of expensive chemicals is very ef can be controlled efficiently.

An embodiment of the invention is described below with reference to the drawings explained in more detail. In which show:

Fig. 1 shows a device according to the invention for monitoring a Chemikali enströmung in partial section and in exploded view,

Fig. 2 is a base body of FIG. 1 in a sectional representation,

Fig. 3 schematically shows the simplified structure of an optical Lichtmessstrec ke,

Fig. 4 shows the image of the light source on the light sensor in different geometrical arrangements,

Fig schematically simplified. 5, the optical system of FIG. 3 with gasge for bottled hose,

Fig. 6a-c are diagrams of the measurement signals with a change of the flow around the Medi of acetonitrile to a Oxidizer,

Fig. 7a-c are diagrams of the measured signals for a water flow with air bubbles,

FIG. 8a-c are diagrams of the measurement signals at a Acetonitrilströmung with Gasbla sen,

FIGS. 9a-c are diagrams of the measurement signals at a Oxidizerströmung with gas bubbles, and

Fig schematically simplified. 10, an optical system with collimator lenses.

Fig. 1 shows a device according to the invention is for monitoring a Chemikali enströmung with a basic body 1 and two sheets 2 and 3 for supporting light sources 4, 5, 6 and two hooks 7, 8 for holding light sensors 9, 10, 11. The base body 1 is formed from aluminum, it being produced by milling from an aluminum block.

The base body 1 is shown in a partial section along the angled section line AA. The boards 2 , 3 , 7 , 8 are shown removed from the base body 1 in the manner of an exploded view in FIG. 1.

The base body 1 is an approximately cuboid body with four side surfaces 12 a, 12 b, 12 c and 12 d and two end surfaces 13 a, 13 b.

In the base body 1 , a through hole 14 for receiving a translucent hose 15 is made , which runs perpendicular to the plane of the end faces 13 a, 13 b and is arranged somewhat eccentrically on the end faces.

Transversely to the through hole 14 are blind hole-like receiving holes 16 , 17 , 18 introduced into the base body 1 . One of the light sources 4 , 5 , 6 , which are designed as photodiodes, is seated in the receiving bores 16 , 17 , 18 . The receiving bores 16 , 17 , 18 each have a cylindrical main section 16 a, 17 a, 18 a, in which the light-emitting section supports the respective photodiode 4 , 5 , 6 . In the direction of the through hole 14 , the cylindrical main portion 16 a, 17 a, 18 a in a conically tapered section from 16 b, 17 b, 18 b over. At the conical sections 16 b to 18 b, there is an aperture hole 19 opening at the through hole 14 , the diameter of which is significantly smaller than that of the respective main section 16 a to 18 a. The aperture bores 19 have a circular cross section and serve as an aperture for the light beam emitted by the respective light source 4 , 5 , 6 bundle.

The receiving bores 16 to 18 are formed on the side surfaces 12 a, 12 b at regions bordering on the side surfaces 12 a, 12 b with a plurality of ring steps. These ring steps are fitting holes that serve for exact positioning of the correspondingly trained photodiodes 4 to 6 . These fo todiodes 4 to 6 pass through their connections 20 corresponding holes in the boards 2 , 3 , so that the photodiodes 4 to 6 are held by the boards 2 , 3 . The boards 2 , 3 are arranged adjacent to the side surfaces 12 a, 12 b of the base body 1 in such a way that one of the photodiodes 4 , 5 , 6 is located in one of the receiving bores 16 , 17 , 18 , the photodiodes 4 , 5 , 6 positively on the ring steps of the receiving bores 16 , 17 , 18 , where their position in the base body 1 and thus with respect to the through hole 14 or with respect to the hose 15 is clearly and very precisely determined.

Diametrically opposite to the receiving bores 16 to 18 each emit at the through bore 14 radiating bores 21 , each of which extends up to one of the side surfaces 12 c, 12 d ( FIG. 2). The radiation bores 21 are arranged in a ge linear extension to the receiving bores 16 to 18 , so that a light beam emitted from the light source through a respective aperture bore 19 , the through bore 14 with the hose 15 therein and the radiation bore 21 can pass through. A light sensor 9 to 11 for detecting the corresponding light beam is arranged at the openings of the radiation bore 21 arranged in the region of the side surfaces 12 c, 12 d. The light sensors 9 , 11 are held by the boards 7 , 8 , which are arranged adjacent to the side surfaces 12 c, 12 d of the base body 1 . The boards 2 , 3 , 7 , 8 are fastened with suitable fastening means, such as screws, to the base body by 1 .

For example, the entire monitoring device can be designed in a size of 1.5 cm × 1.5 cm × 2 cm. On the boards 2 , 3 and 7 , 8 electronics components for controlling the LEDs 4 to 6 or for evaluating the photosensors 9 , 11 can be arranged. With the circuit boards and the electronic components, the size of the monitoring device is 2.5 cm × 2.5 cm × 2.0 cm. Photodiodes are preferably used as photo sensors.

Each pair of light source and light sensor 4 , 9 ; 5 , 10 ; 6 , 11 forms a light measuring section I, II, III which passes through the hose 15 . The light sources 4 , 5 , 6 are controlled by a control device SE. The signals from the sensors 9 , 10 , 11 are evaluated by an evaluation device AE ( FIG. 3).

The light measuring sections I, II are arranged parallel to each other and with a center distance d of 9 mm. The light emitting diodes 4 , 5 and photodiodes 9 , 10 of these two measuring sections I, II are tuned to a red wavelength range of λ ≧ 600 nm. This tuning can be done by providing a color filter and / or by seeing a colored light-emitting diode and / or by tuning the spectral sensitivity of the sensors. Such a color filter can be formed, for example, by a color layer applied to the light-emitting diode.

The light-emitting diode 6 and the photodiode 11 form a light measuring section III, which is arranged perpendicular to the light measuring section I, the two light measuring sections crossing at a point on the longitudinal center line of the hose 15 and being arranged perpendicular to the longitudinal center line of the hose 15 or the passage opening 14 .

The light measuring section III is based on blue light of the light wavelength in the range of λ = 390 to 500 nm tuned.

Fig. 3, the optical system schematically shows the optical measuring section I with the LED 4 and the photodiode 9, which are respectively disposed on an optical axis 22 of the light measuring section I. Like conventional light-emitting diodes, the light-emitting diode 4 is formed from a semiconductor enclosed in a plexiglass body. The plexiglass body looks like a lens. For optimum light yield, light-emitting diodes with strong bundling of the light beam bundle to a maximum radiation angle of less than 30 ° and preferably 15 ° are preferred.

In the area between the light-emitting diode 4 and the photodiode 9 there are the aperture bore, which acts as an aperture 19 , the hose 15 and an outlet aperture 23 . The tube 15 is represented in this optical system by two cylindrical lenses ( FIG. 3), each of the lenses corresponding to the wall section of the tube which is irradiated by the light beam emitted by the light-emitting diode 4 . In the optical system shown in FIG. 3, the tube 15 is filled with a liquid whose refractive index is typically in the range from n = 1.3 to 1.4 and thus differs only slightly from the refractive index of the tube 15 . This liquid column is therefore shown as a cylindrical lens 24 in FIG. 3. The optical system consisting of the two "tubular lenses" 15 and the cylindrical lens 24 focuses the light beam passing through the entrance aperture 19 and exit aperture 23 onto the optical axis 22 (focus F). The photodiode 9 is arranged in the region of the focus F.

Different chemicals have different refractive indices, which is why the position of focus F can vary a little. For the light measuring section according to the invention, it is therefore expedient that the light-sensitive area of the photodiode 9 is large enough to receive the complete bundle of light beams even with a focus F that deviates from the reception plane and to convert its light intensity into a corresponding electrical signal.

In FIG. 4 a number of imaged on the photodiode 9 Figure patterns for different distances between the photodiode 9 and the lens system 15, 24 and the lens system 15, 24 and the light emitting diode 4 is shown. If the focus F differs significantly from the plane of reception of the photodiode 9 , the imaging pattern is approximately circular, since the diaphragms 19 , 23 each have a circular opening. The more precisely the focus coincides with the receiving plane of the photodiode, the more the light beam is focused on a narrow strip-shaped or lens-shaped area. This imaging pattern is thus formed both by the shape of the apertures 19 , 23 and by the focusing of the cylindrical lens system 15 , 24 .

In the light measuring section according to the invention, the two come essentially physical effects of light refraction (refraction) and absorption to the gel tung.

The refraction of light allows the distinction between a gas and a liquid in the hose 15 . Since gas has a refractive index of n = 1, the tube walls look like two weakly refractive cylindrical menisci, so that the light emerges from the tube as a divergent bundle of rays with a low surface intensity ( FIG. 5). If the tube is filled with a liquid which generally has a refractive index of n = 1.3 to 1.4, the lens system 15 , 24 shown in FIG. 3 acts like a strongly refractive cylindrical lens with a short focal length, which the Focused light beam on the photodiode 9 .

Accordingly, a low light intensity is measured in the gas-filled tube from the photodiode 9 , since only a small fraction of the diverging bundle of light beams is detected with the sensor surface. When the tube is filled with liquid, the light beam is almost completely focused on the photodiode 9 , the entire light beam being detected with the photodiode 9 and a correspondingly higher light intensity being measured.

Measurements have shown that the signal distance of the signal from the photodiode 9 between gas and liquid filled hose is 1: 2 and is thus far above the signal-to-noise ratio.

The further physical effect, the absorption, is used to detect the chemical or chemicals in the hose. The optical system shown in Fig. 3, which maps a defined light beam onto the photodiode 9 , allows a very precise evaluation of the spectral absorption. This makes it possible to make quantitative statements about the concentration of certain chemicals. This applies in particular if comparative absorption measurements are carried out with light measuring sections which are matched to different wavelength ranges.

A further increase in the precision of the light measuring path for absorption measurement is achieved in the optical system shown schematically in FIG. 10, in which two collimator lenses 25 , 26 are used in addition to the optical system from FIG Hose 15 is focused, whereby all light rays cross this longitudinal center se and thus run on a diameter line of the hose 15 . Each light beam thus covers the same path length, namely the diameter D of the tube 15 , within the tube. This has the consequence that all light rays are evenly subjected to absorption by the medium contained in the tube. Since the beam path in such an optical system is independent of the refractive index of the medium contained in the tube 15 , such an arrangement is insensitive to the above explained refractive effect. With such a light measuring section it is therefore not possible to distinguish between a gaseous and liquid medium due to the refraction effects and the measurement signal also does not depend on the hose geometry, since the light rays cross the surface of the hose at a right angle. With such a light measuring section, however, the absorption measurement can be carried out extremely precisely.

Below is an application of the device according to the invention for monitoring a chemical flow in a device for synthesizing DNA sequences explained. Such a device for synthesizing DNA Sequences are known for example from WO 00/40330. Reak different chemicals, such as an activator, four under different base reagents A, C, G and T, two different capping reagents s, an elimination reagent, an oxidation reagent, a washing reagent and two un Different rinses, such as argon and acetonitrile. The Ba Sen reagents are synthesized in the reaction chamber to form DNA sequences. Here, dimethoxytrityl (= DMT) is split off. Dimethoxytrityl has an intense red-brown coloring. The concentration of dimethoxytrityl is a measure of the effi ciency of the respective synthesis process.

The device according to the invention for monitoring the flow of chemicals is therefore arranged on the exit side of the reaction chamber and monitors the chemical flow emerging therefrom. The light measuring sections I and II that go together other parallel, are aimed at red light of wavelength λ = 637 nm Right. The light measuring section III depends on blue light of the wavelength λ = 435 nm voted. This blue light corresponds to the absorption band of DMT. From the Measuring signal of light measuring section III, the DMT concentration can thus be calculated the absorption law for light and the geome Delivery factor of the hose is received.

In the present exemplary embodiment, there is no collimator in measuring section III Optics provided, which is why air bubbles can simulate a low DMT color NEN. To be able to rule out such an incorrect measurement, the light Measuring section I air bubbles detected due to the refraction effect. Will with the Light measuring section I detects the presence of air bubbles, so the at the same time from the DMT concentrations measured by the light measuring section III fen.  

If the functionality of the device for synthesis is impaired The finest metal dust can be rubbed off from the DNA sequences and from the chemicals lienstrom be recorded. Such metal dust absorbs both red blue light as well. By a combined evaluation of the light signals Measurement sections I and III can therefore be the presence of metal dust or others Detected impurities and a malfunction of the synthesis device be put.

When changing the reagents to be supplied to the reaction chamber, it is unavoidable that air bubbles get into the chemical flow. Figs. 8a to 8c and 9a to 9c, the signals S respectively show the light measuring sections I through III for a flow of acetonitrile (Fig. 8a-8c) with bubbles or of Oxidizer (Fig. 9a to 9c) with air bubbles. Acetonitrile does not absorb either the red or the blue light, so that due to the refractive effect explained above, only when the air bubbles occur can a reduction in the light intensity be observed, which occurs here in brief fluctuations. A mixture of tetrahydrofuran, phyridine and iodine is used as the oxidizer, which is why the signal of the light measuring path III is absorbed depending on its concentration when oxidizer is present, whereas the signals of light measuring path I and II are at their full level when oxidizer is present. However, the air bubbles can also be seen here due to sudden, brief, strong fluctuations in the signal. These short-term fluctuations of the light measuring section I and II have essentially the same course, which is however offset by a certain time period Δt. Based on the specified distance between the light measuring sections I and II, the time of flight of the air bubbles and thus the flow rate of the chemical flow can be determined from this time difference Δt.

The appearance of the air bubbles can thus be used to precisely determine the chemicals flow and in connection with the inner diameter of the hose to the Er be used by means of the chemical throughput. This allows the determination of leaks or blockages in the synthesis device or an out if the feed pump. This malfunction can be noticed immediately and the synthesis be discarded.  

In particular, with the monitoring device according to the invention Determine the gas content when adding the reagents, creating an individual Refilling the reaction chambers is possible to avoid missing amounts of liquid compensate. In this way, the synthesis yield can be Chains optimized throughout the synthesis and at the same time expensive chemicals be saved. So far it has been common to extend the delivery time of the chemicals longer to be delivered than would have been necessary with a bubble-free conveyance. here through the occurrence of air bubbles is usually sufficiently compensated. The Chemicals are very expensive and are usually not fully used, and in In extreme cases, the excess of chemicals is insufficient, which means that the syn this is impaired. The supply of such excess chemicals can by the provision of the device according to the invention. With the inventor The monitoring device according to the invention can meter the chemicals precisely be performed.

Due to the precise optical arrangement and the multiple light measuring sections it suffices to use the monitoring device according to the invention using Eichmes solutions with any clear liquid, such as acetonitrile, before starting to calibrate a synthesis. A complex electronic calibration with rivers liquids with calibrated coloring are not necessary.

When monitoring the synthesis of oligonucleotides is essentially the Determine DMT share. The proportion of oxidizer and the proportion of IRD700 can be determined in principle. The corresponding spectral ranges, with which the individual substances can be monitored and the types of corresponding LEDs and photodiodes are in the following tables specified for the measurement of the concentration and the measurement of the gas bubbles.  

Concentration measurement

Measurement of gas bubbles

Each time an oligonucleotide is successfully synthesized, a DMT group is removed splitted. The amount of DMT is thus proportional to that which is fully synthesized Oligonucleotides. When evaluating the measurement signals, it can therefore be determined by of the integral over the DMT portion a measure of the number of successful Syntheses of the oligonucleotides can be determined.

The charts shown to 6c in Fig. 6a show a change from acetonitrile to Oxidizer. The measurement signals of a light measurement section sensitive to blue light are shown in FIG. 6a and the measurement signals of a light measurement section sensitive to red light are shown in FIGS. 6b and 6c. From Fig. 6a shows that with blue light, the chemicals acetonitrile and oxidizer, and the air bubbles in each case causing a difference currently measured level may be so that the presence of a particular chemical clearly detected. In contrast, the two chemicals are equally transparent to red light ( FIGS. 6b, 6c), so that red light is suitable for the clear detection of air bubbles. The light measuring distances behave similarly when water is passed through, which is transparent to both red and blue light ( FIGS. 7a to 7c).

The invention is based on an embodiment with three light measuring stretches ken described. Within the scope of the invention, of course, only only two light measuring sections or more than three light measuring sections can be provided. The greater the number of light measurement sections, the more complex the monitoring tasks can be accomplished. Increasing the number of light measurement sections allows in particular the detection of different chemicals.  

reference numeral

1

body

2

circuit board

3

circuit board

4

light source

5

light source

6

light source

7

circuit board

8th

circuit board

9

light sensor

10

light sensor

11

light sensor

12

a,

12

b

12

c,

12

d side surface

13

a,

13

b face

14

Through Hole

15

tube

16

location hole

17

location hole

18

location hole

19

orifice bore

20

Connection from one of the light sources

21

Abstrahlbohrung

22

optical axis

23

exit aperture

24

cylindrical lens

25

collimator lens

26

collimator lens

Claims (16)

1. Device for monitoring a chemical flow, with
a base body ( 1 ) which has a tubular recess ( 14 ) for receiving a translucent tube ( 15 ),
at least two light measuring sections (I, II, III), each light measuring section (I, II, III) being represented by a light source ( 4 , 5 , 6 ) and a light sensor ( 9 , 10 , 11 ) for measuring the light intensity of the received light beam is, and the light source ( 4 , 5 , 6 ) and the light sensor ( 9 , 10 , 11 ) of a light measuring section (I, II, III) are arranged diametrically to the tubular recess ( 14 ) such that one of the light source ( 4 , 5 , 6 ) emitted light beam from the light sensor ( 9 , 10 , 11 ) is received, and
an evaluation device (AE) which evaluates the light signals emitted by the light sources ( 4 , 5 , 6 ) and received by the light sensors ( 9 , 10 , 11 ) to determine a flow rate and / or a chemical concentration. 2. Device according to claim 1, characterized in
that the light source ( 4 , 5 , 6 ) and the light sensor ( 9 , 10 , 11 ) are positioned in such a way
that the light beam emitted by the transmitter is formed by the translucent tube ( 15 ) filled with a liquid, for example on the light sensor ( 9 , 10 , 11 ). 3. Device according to claim 1 or 2, characterized in that the light sources ( 4 , 5 , 6 ) are light emitting diodes. 4. Device according to one of claims 1 to 3, characterized in that the light sensors ( 9 , 10 , 11 ) are photodiodes. 5. Device according to one of claims 1 to 4, characterized in that the light measuring sections (I, II, III) are at least provided with an aperture ( 19 , 23 ). 6. The device according to claim 5, characterized in that an aperture ( 19 , 23 ) is arranged adjacent to each light source ( 4 , 5 , 6 ) and adjacent to each light sensor ( 9 , 10 , 11 ). 7. The device according to claim 5 or 6, characterized in that the diaphragm ( 19 , 23 ) is designed as a circular diaphragm. 8. Device according to one of claims 1 to 7, characterized in that provided in at least one of the light measuring sections collimator lenses ( 25 , 26 ) for bundling the light beam emitted by the light source ( 4 , 5 , 6 ) onto the central axis of the tubular recess are. 9. Device according to one of claims 1 to 8, characterized, that two of the light measuring sections (I, II) in the direction of the chemical flow by ei NEN certain distance are arranged offset. 10. The device according to claim 9, characterized in that the light sources ( 4 , 5 , 6 ) and the light sensors ( 9 , 10 , 11 ) of the light measuring paths arranged offset in the direction of the chemical paths are each matched to the same wavelength range. 11. The device according to one of claims 1 to 10, characterized in that the light sources ( 4 , 5 , 6 ) and the light sensors ( 9 , 10 , 11 ) of the light measuring sections arranged offset in the direction of the chemical sections to a wavelength range with λ ≧ 600 nm are matched. 12. The device according to one of claims 1 to 11, characterized in that two of the light measuring sections (I, III) intersect at a point on the central axis of the tubular recess ( 14 ), and the light sources ( 4 , 5 , 6 ) and light sensors ( 9 , 10 , 11 ) of these light measuring sections are each matched to different wavelength ranges. 13. The device according to one of claims 1 to 12, characterized, that the light measuring sections (I, II, III) are each provided with a color filter. 14. Device according to one of claims 1 to 13, characterized in that the base body ( 1 ) has fitting bores for receiving the light sources ( 4 , 5 , 6 ), so that the position of the light sources ( 4 , 5 , 6 ) with respect to tubular recess is clearly defined. 15. The apparatus according to claim 14, characterized in that the fitting holes by means of a circular cross-section through bore ( 19 ) are connected to the tubular recess, these through holes each forming an aperture. 16. Use of a device according to one of claims 1 to 15 in a pre Direction for synthesizing DNA to make the chemical flow a reaction to monitor the chamber.